Cornea

Cornea: Suture-less transplantation of the ocular surface

Have you ever looked at your own eyes, probably through a mirror? If not, have you ever tried to see how an eye look like by peeping into your friend’s eyes? In either of these occasions, you might have wondered how we see million and one things around us, since birth by such a small structure.

Although eye is one of the smallest structures in our body, it has a very complicated function to carry out-vision, and that is why it is made up of several elements which have their own part to do. Poor functioning of a tiny element of this can lead to a complete impairment of vision since all of these work as a network which coordinate well with one another.

Cornea, also referred to as ‘Window to the world’ is the front most part of the human eye which appears like a thin, clear and transparent, dome shaped membrane. Light rays enter into the eye initially through this part which will then be directed further inside to get refracted through the eye lens.

Cells of the cornea are very fragile and they can get damaged easily even by minor insults. Unfortunately, the dead cells will not grow again, giving rise to scarring of the cornea, irregular shape and inflammatory signs including pain, blurred vision which can ultimately cause blindness. Being one of the most externally located parts in our body, cornea is often exposed to numerous harmful irritable agents which can give rise to infections, diseases and even malignant conditions.

Scarring of the cornea can occur due to two main reasons including Fuch’s corneal dystrophy and trauma following Cataract and Glaucoma surgeries.

Fortunately, we are blessed with numerous, quality-rich eye banks all over the country with the capability of getting cornea and its function restored following damage or any anomalies, thanks to the latest development of technology related to ophthalmology. This is usually carried out in a process by which a person who recently passed away, donates his/her cornea and it is used to correct the vision of another individual by a successful corneal transplantation. This is more or less similar to what you might have heard about organ transplantations.

The type of corneal transplantation indicated in affected patients will differ according to the extent of damage.

• Full thickness scarring- Corneal transplantation with sutures
• Partial thickness scarring (Fuchs’ Dystrophy and Keratoconus)-Suture-less corneal transplantation

Suture less Corneal Transplantation (DSAEK)

Are you a ‘female’ over ‘50 years’ who has a ‘positive family history’ for a condition called Fuch’s Dystrophy? Orare you a person who recently underwent a surgery for cataract or Glaucoma now experiencing some sort of a discomfort along with difficulty in seeing properly?

If yes, you are also at a high risk for getting this particular impairment of the cornea which can more or less impair the vision, gradually progressing towards a complete blindness.

Therefore, it is highly important to be aware of issues related to cornea and how they would present, in order to seek immediate medical advice if any similar changes are noted.

Fuchs’ (Fook) corneal Dystrophy

Fuchs’ (Fook) Dystrophy is a condition where ‘pump cells’(endothelial cells) in the endothelial layer (inner most part) of cornea are damaged resulting in a swollen cornea with cloudiness, glare and discomfort of the eye. Most often affecting both eyes, this condition usually progresses over years without giving rise to any signs and symptoms until a severe state is reached where the vision is significantly impaired.

Patients who are diagnosed with Fuch’s or other conditions with a partial involvement of the cornea can now undergo a less invasive operation known as DSEK, this partial thickness transplantation has replaced traditional full thickness transplantation which is quite invasive.

DSEK-Descemet’s Stripping Endothelial Keratoplasty

This is a partial thickness corneal surgery in which a thin functional layerof donor’s corneal tissue is inserted into affected eye to replace the corresponding damaged inner layerof the patient’s cornea, surgery is through a small surgical incision made. No sutures are required and the layer is secured in position with air.

A special positioning following the surgery is recommended (lying down on your back facing the ceiling) since only air has been used to safe guard the corneal layer in the eye instead of traditionally used sutures. This air usually dissolves by the end of the third day. The patient can get back to normal routine work (within about 1-2 weeks) as this procedure ensures faster recovery.

However, it is important to remember that, this surgical intervention is only indicated in patients with a damage to the endothelium whereas the other layers are completely healthy. In fact, those who present with extensive clouding or scarring are preferably directed towards a full thickness replacement to reach a better outcome.

Advantages of DSEK

• A comparatively lesser time taken to complete the surgery which is usually less than 30 minutes
• Surface of the eye will be kept intact during the surgery, creating a better resistance to injury and infection
• Only the endothelial layer accounting for 5% of the entire cornea will be replaced by the surgery so there will not be any major change in the initial refraction (the capacity of the light to bend when passing through the lens), means the discomfort to the eye following the surgery will be minimal.
• suture-related problems will be nil.
• Healing of the wounds and visual recovery are comparatively faster and better than the traditional method (few weeks to months).
• Since the incision is very small, the possibility of break opening of the wound following a trauma is highly unlikely.
• Less incidence of complications such as post-operative astigmatism (abnormal shape of the cornea)
• Very low incidence of rejection (patient’s immunity fighting against the donor’s cornea resulting in a rejection)
• 90% of the patient’s own cornea will be retained following the surgery

DSEK has largely replaced conventional penetrating keratoplasty and in now surgery of choice for most (but not all) corneal transplant procedures.